Hospital president and CEO Frank Kelly spoke Tuesday of Herrera's "iconic stature" at the hospital. Along with a core of other dedicated doctors -- among them Belsky, Paul Kunkel, Benjamin Egee, Raphael Schwartz and Nelson Gelfman -- Herrera helped modernize the hospital, improving medical practices, urging the hospital to create teaching and education programs for its staff and connecting it to the international world of scientific research.

"When I talk to people about that group, his name is one of the ones that always comes up," said Carl Peterson of Brookfield, the hospital's former vice president of marketing and communication, who is writing a history of the hospital.

Herrera was chairman and director of the hospital's Department of Laboratory Medicine and Nuclear Medicine for more than 30 years, starting there in 1960 and retiring in 1991. He held the title of chairman emeritus after his retirement.

His colleagues credit him with creating the first modern pathology laboratory at the hospital, including installing the first system to computerize its data. Kelly called Herrera "a brilliant visionary" because of his work in creating the hospital's nuclear medicine program, and his collaboration with the World Health Organization.

He was also an advocate for making Danbury Hospital into a teaching institution, where young medical students could train. The hospital's first residency program was in pathology, and Herrera, along with his work at the hospital, taught pathology at Yale University Medical School, New York Medical College, the University of Connecticut and the Universidad Nacional Pedro Henríquez Ureña in his native country of the Dominican Republic.

"He had a great interest in science and learning," said his son, Mario, of Danbury.

"He would stop doctors in the hall, and grill them about their work," Peterson said. "Then, he'd encourage them to teach."

Mario Herrera said his father grew up in humble surroundings in the Dominican Republic. One of seven children, he worked hard to get into medical school. A Fulbright Scholarship brought him to Vermont, where he befriended John Creasy, who came to Danbury Hospital to work with Herrera and eventually became the hospital's president as it grew through the 1970s and 1980s.

By all accounts, Herrera was a Old World gentleman, courtly and well-spoken. But he was also a man of decided opinions who was not afraid to express them, Belsky and Blansfield said.

"But he was almost always right, so there was no use arguing with him," Blansfield said.

"You'd meet him, and your impression, right away, was that he was a brilliant man," Kelly said.

When not running a pathology lab, creating a nuclear medicine program, lecturing, writing, doing research, and collaborating with the WHO, Herrera and his late wife Clara raised four children. He loved classical music, Mario Herrera said, and was an avid photographer and golfer.

And at parties, when the merengue from his native Dominican Republic played, he and Clara out-danced everyone else.

"They were simply great dancers," Belsky said. "When they got out of the floor, everyone else just stopped and stared."

Mario Herrera said he can remember himself as a child, visiting his father in Danbury Hospital, running around the hallways of its one aging building. If the hospital is much changed from that, it was because of his father, and others, who got it started in a new direction, he said.